


Notes of an Old Mistake

by backslashdelta



Category: Glee
Genre: Anal Sex, Angry Sex, Angst, Blaine Friendly, Bottom Sebastian Smythe, Enemies to Friends, Gay Sex, Hate Sex, Hook-Up, I'm proud of myself for that, M/M, New York City, Past Blaine Anderson/Kurt Hummel, Pining, Porn With Plot, Slut Shaming, Smut, Sort of at least, Top Kurt Hummel, but like barely in the past, it's a one-shot so how much pining can there really be?, mentions of Blaine Anderson - Freeform, sort of but nothing TOO severe I don't think, there are definitely some hard feelings but you will not find Blaine hate here, they don't really hate each other but at least one of them wants to so I think it counts, yes there really is plot I promise
Language: English
Status: Completed
Published: 2021-01-10
Updated: 2021-01-10
Packaged: 2021-03-14 14:26:54
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,553
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28672221
Author URL: https://archiveofourown.org/users/backslashdelta/pseuds/backslashdelta
Summary: The night Kurt calls off his engagement, he goes out for a night in the city in the hopes it will help him forget about his problems. A random encounter with an old high school rival brings back some unexpected feelings for both of them.
Relationships: Kurt Hummel/Sebastian Smythe
Comments: 12
Kudos: 65





	Notes of an Old Mistake

**Author's Note:**

  * For [PourALittleWater](https://archiveofourown.org/users/PourALittleWater/gifts).



> Writing Kurtbastian smut in my 2021? It's more likely than you think.
> 
> A gift for the wonderful BG because I wanted to write something for her. She wanted angsty pining and wasn't opposed to some smut, and given the opportunity to write smut I'm basically incapable of NOT writing it, so, here we are. I hope this is everything you hoped for and more. I got a little carried away with this story and it's longer than I intended, but I'm pretty happy with how it turned out.
> 
> We're bouncing back and forth between perspectives, because apparently that's how I write now. Each line break is a perspective switch, and we're starting with Sebastian.

He sees him for the first time in a mediocre New York club, grinding against a man with black hair and eyes ringed in kohl. He doesn't even realize it's Kurt at first, he's just staring unabashedly at the lithe figure and his sinfully tight pants, but then Kurt turns to grind his ass back into the other man and Sebastian gets a look at his face.

And he freezes, because while the other man definitely looks older now than he remembers, that's _definitely_ Kurt.

And he's _hot_.

Sebastian has to admit that he's always found Kurt attractive. Of course he never would have admitted it back in high school; while he was confident enough to be out and proud and gay, he hadn't yet developed the confidence to let the world know he thought someone like Kurt was attractive. Kurt, who was also openly gay, but wasn't afraid of the more feminine, never cared what people thought of him, did what he wanted and looked how he wanted and that fearlessness in and of itself was half the appeal. So instead of acknowledging his attraction to the other boy he'd attacked him. But Kurt was strong, and though Sebastian's verbal assaults and sexual advances on Blaine seemed to shake him at times, he never broke.

And it might have been more than a simple attraction. The more time he spent around Kurt, the more _fascinated_ he was with the other boy, and as much as he denied it at the time, he knows now that he had feelings for him.

He feels awful for how he treated Kurt in high school.

It was never about Kurt, it was about _him_ , and Kurt put up with enough from everyone else, he didn't need it from Sebastian, too. And he knows he can never take it all back, but maybe he can apologize. He owes Kurt that much.

It's that moment when Kurt locks eyes with him, and then _Kurt_ freezes as they stare back at each other for a moment, neither man sure what to do. Then Kurt's dance partner is saying something – and for the first time, Sebastian really realizes that it's _not Blaine_ – and Kurt drags his eyes away from Sebastian, says something back, and then they're walking off the dance floor and into the crowd.

It's now or never, he figures, because if Kurt leaves this bar and Sebastian doesn't talk to him, he may very well never see him again. He pushes off from the wall he was leaning against and weaves his way through the clusters of men in the direction Kurt was heading. Eventually he catches up, just in time to see Kurt slipping out through the door.

He follows the two men outside onto the sidewalk.

"Kurt, wait!"

Kurt stops, pauses a moment before he turns to face Sebastian, and the black-haired man gives him a look somewhere between confused and concerned. "What do you want, Sebastian?"

"I wanted to apologize." He feels like an idiot now, chasing an old high school crush out into the streets of New York at 1am on a Saturday morning to apologize, but he's done it now so he might as well say it.

Kurt quirks an eyebrow ever so slightly as he stares back; but then he doesn't reply, just turns again and loops his arm through the other man's and takes off down the sidewalk.

"Kurt!" Sebastian says, following behind, still feeling like an idiot, still feeling like he has to do this.

" _What?_ " Kurt snaps, not pausing before he whirls around this time to look at Sebastian again, and he hadn't been expecting Kurt to stop so quickly so he's close now, so close that he can feel Kurt's breath on his cheek when he says, "You think I need an apology from you? Because I _don't_."

"No, it's not that, I just–" Sebastian starts, but Kurt doesn't let him finish.

"I don't _care_. Don't waste your breath. Goodbye, Sebastian."

And then Kurt and the other man are walking off down the sidewalk again as Sebastian stands motionless and watches them disappear into the city night.

* * *

He knows he was harsher than was absolutely necessary, but it was _Sebastian Smythe_ , and after the evening he'd had, he just _couldn't_.

Of all nights, he had to run into Sebastian the night he broke up with Blaine. He loves Blaine, even now he still loves him, but sometimes love just isn't enough. It had killed him to break Blaine's heart the way he did, but he didn't have another _option_. He'd rather Blaine hate him than grow to hate Blaine himself. So he'd broken up with his fiancé – _ex_ -fiancé, he reminds himself – and gone to Elliott's, and Elliott had decided they needed a night out. He figured it couldn't hurt, it would be a good way to take his mind off things because all he wanted to do was stop _feeling_ , but then _Sebastian Smythe_ had been there, had the nerve to try to apologize as though he wouldn't be the first one to try to pounce on Blaine if he knew, tell Blaine all the reasons he _should_ hate Kurt, and the thought alone made him sick.

The worst part was that maybe Blaine would be better off with Sebastian after all. Sebastian is confident and fun and Kurt can't deny that the other man is attractive, even more so now than back in high school.

"Kurt, hey, slow down," Elliott says, tugging at his arm to make him slow his pace, "what's going on?"

"I can't," Kurt says, letting Elliott slow him down until they're just standing in the middle of the sidewalk facing each other.

"Can't _what_ , Kurt? Who was that?"

"Sebastian."

Kurt can see the eye roll Elliott is suppressing. "Yeah, I got that. But who _is_ he?"

Kurt takes in a breath, takes a step closer to the building to his right and leans his back against the wall. "This guy in high school, he... _god_ I hate him."

"Hey, high school was a long time ago. Forget about him," Elliott says encouragingly, hopefully.

"He tried to steal Blaine," Kurt blurts out.

"He what?" Elliott asks with a frown.

"When we were in high school, he _hated_ me, I don't know why, and he just... every chance he got, he tried to steal Blaine, and I just... maybe I should have let him."

"Hey, no," Elliott says, "don't say that."

"Not like it matters now anyway," Kurt says, sliding down the wall until he's sitting on the ground, "he can have him."

"Kurt," Elliott says empathetically, crouching down beside him, "are you sure you made the right decision?"

Kurt sniffles a little, stares up at the sky and blinks back the tears threatening to fall. "Yeah, I am, I just... it sucks."

Elliott's voice softens when he speaks again. "I know. C'mon, let's get you home and in bed. Things will look better in the morning."

* * *

He hasn't been able to stop thinking about that night all week. Everything about it feels surreal. He hasn't thought about Kurt in so long, and then he was _there_ , with his skin-tight jeans and perfectly coiffed hair and sapphire-blue eyes and _fuck_.

There's that crush again.

Exactly what he _doesn't_ need is this fixation on the boy from high school that he'll probably never see again. He needs to get Kurt out of his head, because this is ridiculous, but he _can't_. All he can think about is _what if_ : what if he hadn't been such an asshole in high school, what if he'd been able to acknowledge his feelings for Kurt at the time, what if he'd _told him_? Or what if Kurt hadn't walked away that Friday night, had stayed and let Sebastian apologize and they'd talked, and–

No. No, he shouldn't be thinking about any of this, he should be forgetting about _all_ of this because that's all it is: what-ifs.

He rounds the corner in the stairwell and nearly collides with someone on their way down.

"Shit, sorry," he says, pulled from his thoughts as he steadies himself and looks at the other person, and...

It's Kurt.

"Kurt," he breathes, because he's not sure what else to say.

He sees Kurt's jaw tighten, his eyes narrow as he registers that it's Sebastian. "What are you doing here?"

"I... live here," Sebastian says dumbly.

He sees Kurt falter for a moment, but it's masked again quickly. "Since when do you live here?" Kurt asks, tone not quite as sharp.

"Since a couple months ago," Sebastian answers, "what are _you_ doing here?"

"I– my friend lives here."

"The guy you were with the other night?" Sebastian asks, because it's been bugging him ever since.

"Not that it's any of your business, but yes."

"No Blaine?" He knows the moment the words pass his lips that he shouldn't have said them, but it's too late. Kurt stiffens, his stare turns icy and he purses his lips. He doesn't say anything, just moves to shove past Sebastian, but Sebastian reaches out and grabs his arm to stop him. "Kurt, would you just let me–"

"You know what Sebastian," Kurt spits, and they're so close right now, Sebastian's hand gripping Kurt's arm and he can feel the tension in his muscles, "if you care so much about Blaine then maybe you should be talking to _him_ , not me."

Sebastian feels the irritation flare inside him because he's just _trying_ to be nice, and as much as his renewed feelings have been torturing him for the past week he still has enough self respect to not let himself be treated like this.

"Maybe I don't _want_ to talk to Blaine, did you ever think about that, Kurt? Maybe I actually wanted to talk to _you_."

Kurt scoffs, but Sebastian doesn't miss his expression faltering for just a moment before his face is composed into his trademark icy glare. "As if, you think I don't remember how much you wanted him back in high school? Well, congratulations, you can have him."

He wasn't _quite_ expecting that, but then again, he's not all that surprised, either; Kurt doesn't seem the cheating type, and he _was_ getting pretty close with that friend of his on the dance floor the other night.

"I don't want him, Jesus Kurt, if you would just fucking _listen_ then I could–"

Kurt cuts him off again, but instead of with words it's with lips, lips pressed rough and hard against his own, a hand coming up to grip his hair tightly and hold him there. It takes him a moment to react, caught off-guard by the sudden kiss, but then he does, kissing Kurt back with all the ferocity that Kurt is giving, and he finds his hands snaking their way around Kurt's waist, pulling the two men closer together. Kurt backs him into the wall of the stairwell, back pushed up against the cool concrete and Kurt's firm chest against his own.

The kiss is electric, like no kiss Sebastian has ever had, and that's not for lack of men to kiss. It feels like an eternity and an instant all at once, giving and taking and nipping and sucking, and then Kurt pulls back and his face is still cold and hard and his eyes are dark, so dark, and there's a fire there that Sebastian hasn't seen before and _fuck_ he needs this man.

"You live here?" Kurt asks, voice low.

"Yeah," Sebastian says with a nod, panting a little; they both are.

"Well?"

He can't believe this is happening, absolutely _cannot_ believe it, and there's no chance in hell he's passing up on this opportunity. "Yeah, right," he says, and then they're continuing up the stairwell toward Sebastian's apartment.

* * *

The second Sebastian's door is closed, Kurt is on him, pushing him up against it and sealing their lips together again.

Fucking _Sebastian Smythe_. Of all the people in this entire city, it's _Sebastian_ that he has to keep running into. It's not even that he hates the guy; sure, he never liked him, but he hasn't even _seen_ him in years. He knows it wasn't really about _him_ , it was about Sebastian being young and immature and insecure and an asshole, and honestly he'd barely thought about the other man in years, either. But then everything had happened with Blaine, and Sebastian was just _there_. There with his toned arms and his emerald eyes and his _apologies_ reminding Kurt what Blaine could have, and it's easier to hate Sebastian for it than to acknowledge the things he's really feeling.

He hadn't even realized, _really_ realized, that he was kissing Sebastian until he was, had him pressed up against the wall in the stairwell, and there was a split second where he'd questioned himself, wondered what the hell he was doing, this is _Sebastian Smythe_ , but... it felt _good_. He couldn't deny that Sebastian was attractive – even in high school, despite all the low blows to the other man's appearance, Kurt could recognize an attractive guy when he saw one – and from their very limited interaction over the past week he didn't seem _completely_ intolerable anymore, and maybe this would even help him feel better. By that point he could tell Sebastian was into it, and he'd be lying if he said that wasn't a bit of a boost to the ego. He'd _also_ be lying if he said he wasn't starting to feel the impact of a less-than-regular sex life since he and Blaine had split; sure, it hasn't been _that_ long, but... well, a man has needs.

And Sebastian seems more than willing to help satisfy them.

Sebastian pulls away from the kiss, and Kurt is about to complain until the other man's mouth reattaches itself to Kurt's neck and his breath catches with a soft groan as Sebastian bites gently at the skin over his pulse.

He definitely needs this.

"Shirt," he gasps, tugging up on the hem of Sebastian's shirt.

Sebastian gets the hint, and Kurt backs off just enough to allow Sebastian to pull his shirt off over his head and toss it aside, and then their lips are together again as Sebastian works open the buttons of Kurt's shirt.

Kurt is shirtless in no time, Sebastian's agile fingers making fast work of it, and then Sebastian is sucking at Kurt's collarbone and Kurt _moans_ , high-pitched and needy.

"Knew you always wanted this," Sebastian says.

Kurt can hear the smirk in his voice. "Fuck you," he spits out, trying to keep his voice steady, but Sebastian's mouth is making it hard.

His hands are at Sebastian's waist now, working open his jeans and pushing them down with his boxers, letting Sebastian's cock spring free and he pauses for a moment just to _look_.

"See something you like?" Sebastian asks, but he sounds more breathless than smug.

Kurt ignores him. "Lube?"

Sebastian laughs. "Anxious for a dick in your ass?"

Kurt scoffs. "In your dreams, Smythe. I'm not the one about to get fucked here."

" _Fuck_ ," Sebastian breathes, all lust and desire, and then he's pushing off the wall and walking further into the apartment, disappearing through a door and coming back a moment later with a bottle of lube and a condom, handing them over to Kurt.

Kurt pushes Sebastian against the door again, this time facing away so he has full access to his ass, and he has to admit it's a damn good ass. He squirts some lube onto his fingers and then reaches down, slides a finger over Sebastian's hole, and he feels the other man shiver in anticipation.

"Gonna fuck you so hard," Kurt says, leaning in to whisper in Sebastian's ear as he continues stroking with his finger, "gonna stretch you open for me then bury my cock in your ass and fuck you right here against this door."

" _Kurt_ ," Sebastian moans, and he hadn't realized how hot it would be to hear Sebastian say his name until now but _fuck_ it's hot.

He buries his face in Sebastian's neck to muffle his groan, and then he pushes a finger in, feels the tight ring of muscle clenching around his finger as he slowly pushes further, listening to Sebastian's quickening breaths, until he's buried to the knuckle. And then he's thrusting in and out, stretching him, and Sebastian is trembling and whimpering under his touch as he adds a second finger, then a third, until Sebastian is good and open for him, taking his fingers easily, desperately.

He doesn't bother to ask if Sebastian is ready for him, honestly doesn't really _care_ at this point. He pulls his fingers out, eliciting a hiss from Sebastian, and he wipes them on his thigh before undoing the button of his pants, sliding the zipper open and pushing down his pants and briefs just enough for his dick to spring free. He grabs the condom from where he'd dropped it on a side table near the door, rips it open and rolls it down over himself, breath stuttering as he strokes languidly.

"So are you going to fuck me or not?" Sebastian asks impatiently, but Kurt can hear the desperation there, too, and _that_ he likes.

"Maybe if you ask nicely," he shoots back.

"Like hell I'm asking nicely," Sebastian says with irritation.

"Then maybe I won't," Kurt smirks.

"Kurt, come on," Sebastian says, almost _pleads_. Almost.

"Was that you asking?" he muses, quirking an eyebrow at the man still leaning against his front door, ass pushed back in offering for Kurt.

"That was me saying you'd better get over here and fuck me right now," Sebastian huffs.

"I didn't hear a please," Kurt says, and he's having fun with this now. He never thought he'd be in this position – and with Sebastian Smythe, of all people – and it makes him feel kind of powerful.

Sebastian stares back at him defiantly, but Kurt looks back with equal determination, and they stay there locked in a staring match until, finally, Sebastian mutters a sarcastic, "Please."

He knows it's the best he's going to get from the other man, and he _does_ really want to fuck Sebastian, so... he'll take it.

"Well, since you asked so nicely," he says, stepping back over to Sebastian and lining himself up at his entrance.

"Fuck you," Sebastian counters, though Kurt is surprised to hear that there's no real heat in the words.

"That's the plan," Kurt replies, and then he's pushing in slowly and they're moaning in unison as Kurt buries himself inside Sebastian. "You're so tight," Kurt says, voice strained as he feels Sebastian squeezing around him.

"I get that a lot," Sebastian says back, voice equally strained, "now would you _move_?"

"You're such a slut," Kurt says as he pulls back out partially before slamming back into Sebastian, "so needy, how many people have you let do this to you?"

"Wouldn't you–" Sebastian grunts, cutting himself off with a gasp as Kurt pounds into him again, "– wouldn't you like to know."

"Not really," Kurt shoots back, picking up his pace, "you've probably lost count."

"I keep a journal," Sebastian says back, and Kurt is pretty sure it's sarcastic but he honestly wouldn't put it past the guy.

"Surprised you talk to them long enough to learn their names."

"Fuck you," Sebastian spits again, and clearly Kurt has started to get under his nerves a bit but he can't bring himself to care because it just feels _good_. It's not that he even really thinks the things he's saying are true, it's just that he feels so _much_ and it's a relief to get _something_ off his chest, even if that something isn't what's really been bothering him.

"Just a desperate whore," Kurt continues as he feels himself building closer to release, "you'll let anyone with a dick who gets close enough fuck you, won't you?"

"What the fuck, Kurt? If I wanted a lecture I'd call my parents," Sebastian complains, but then Kurt reaches around to stroke him and Sebastian is lost to breathy moans.

"It was never about Blaine, was it?" Kurt asks, and he's not sure where it's coming from anymore, he doesn't _want_ to be thinking about Blaine right now of all times, but the words are coming and he can't stop them. "You never wanted him, you just wanted someone's cock in you."

"Kurt," Sebastian pleads, and through the swirl of lust and anger and hurt clouding his own mind he recognized the lust in Sebastian's tone but also the conflict there.

He still doesn't care how Sebastian feels about this.

"Just needed a cock in your ass," Kurt pants, voice getting higher and breathier as he approaches his release, and he continues to stroke Sebastian as he pounds into him, "like a desperate whore, you'd do anything for it. You never cared about anyone else, just cared if you got your ass filled."

" _Kurt_ ," Sebastian gasps again, all high and needy and desperate.

And that's what does it. Kurt thrusts into Sebastian one final time as he feels the orgasm coursing through his body, hot and electric as he buries himself inside the man pressed against the door. He strokes Sebastian several more times and then he feels the muscles in the other man's ass contracting around him, feels Sebastian's hips stuttering and the come dripping down onto his hand still wrapped tightly around Sebastian's cock.

They stay there for a moment, leaning against the door and breathing hard, until the post-orgasm haze clears and Kurt realizes exactly what just happened.

* * *

Sebastian feels Kurt pull out of him, and he winces slightly at the sudden emptiness. He stays where he is, still trying to catch his breath and figure out exactly _what_ just happened, because that was a lot. He knew going into this that Kurt must have hated him, and that he'd had good reason to, but he still hadn't been expecting some of the things Kurt had said.

From the corner of his eye he sees Kurt leaning against the wall next to him before sinking down to the floor. And then he hears sniffling, and he turns his head to look, and... is Kurt _crying_?

"Kurt?" he asks, voice still a little weak.

Kurt doesn't respond, just turns his head away and takes in a shaky breath.

"Kurt, are you okay?" Sebastian asks again, voice stronger now as he straightens up from the door and turns to get a better look at the other man sitting on the floor, knees curled to his chest.

"Fuck off," Kurt says, but then he sniffles again and wipes at a fresh set of tears with the back of his hand.

"Hey, what's wrong?" he asks, a little bewildered as he crouches down and takes a seat next to Kurt.

"Nothing," Kurt says stubbornly, and this is so obviously _not_ nothing.

He sighs, then leans back against the wall, tipping his head up to the ceiling. "You were only partly right, you know."

"What?" Kurt asks, and in his peripheral he can see the other man looking at him now.

"It was never about Blaine, you were right about that," Sebastian elaborates, because he figures he'd better say this now that Kurt is finally listening to him, "but it wasn't just sex, either. It was about you."

He feels Kurt staring at him, but the other man doesn't say anything, so finally he pulls his eyes from the ceiling to look back at Kurt.

"Yeah, right," Kurt scoffs, finally, looking away again.

"I'm serious," Sebastian argues, "it was about you. Blaine was hot, sure, but... _you_."

"Me what?" Kurt asks, still looking away, but Sebastian can tell now that Kurt is really interested, really listening.

And he figures that it's all or nothing, because he doesn't know if he'll ever get a chance like this again.

"Kurt, you're just... _you_. I mean, have you _looked_ at you? Ever? You know I didn't mean a word I said, right? I was just... scared, I guess. I didn't know how to deal with any of it."

"Any of _what_?"

"My feelings," he says, then sucks in a breath because he might as well say it plainly, "for you."

"Your _what_?" Kurt asks, head finally swiveling to look back at Sebastian in disbelief.

"Oh come on, Kurt, there's no way you didn't know," Sebastian says.

"How would I have _known_?" Kurt asks. "Was it the never-ending stream of insults aimed at everything about me, or the constant attempts to steal my boyfriend that was supposed to give it away?"

Sebastian winces a little. "I really am sorry about that," he says, though he knows it probably doesn't mean much.

Kurt studies him carefully for a moment, scrutinizing, until he breaks eye contact and tips his head up. "I never really hated you, you know," he admits.

"What?" Sebastian asks dumbly, because _that_ surprises him.

"I mean, don't get me wrong, I didn't _like_ you, but... it was never really about you. I think I was just scared Blaine would realize there was someone out there better for him than I was. I mean, you were this smart, charming, attractive guy and you were right _there_ practically begging him to leave me for you, and he could have, I never really knew what was stopping him. He would have been better off without me."

"You think I'm attractive?" Sebastian asks with a smirk.

Kurt rolls his eyes. "That's what you got from that?"

"It really wasn't about him," Sebastian says, voice softer, because he wants Kurt to know that he means it.

Kurt doesn't respond.

"Let me prove it to you."

"What?" Kurt asks, pulling his eyes back down from the ceiling to level Sebastian with a confused look.

"Let me prove it was never about him, it was about you."

"And exactly how are you going to do that?" Kurt asks skeptically.

"Let me be your friend." He wants more than that, so much more, really, but he needs to be realistic. Kurt is clearly not ready for a relationship right now, and Sebastian doesn't want to be a rebound. If they're ever going to be together, then he wants Kurt to really _want_ it, he wants it to really mean something. And if Kurt never wants it, then that's fine, too.

"You want to be _friends_?" Kurt asks, quirking an eyebrow.

"Yeah," Sebastian agrees easily. "I mean, I'd like to be more than friends, eventually, maybe, but... I think friends is a good start."

Kurt stares at him for a long moment, as though trying to figure out what he's really thinking, and Sebastian isn't sure what conclusion he comes to but apparently it's good enough because he just lets out a breath and says, "Okay."

"Seriously?" Sebastian asks, because he really didn't expect Kurt to agree that easily.

"Did you want me to change my mind?" Kurt asks, tilting his head to the side and smirking just slightly, "Because I can."

"No take backs," Sebastian says as he feels a grin spreading over his face.

Kurt rolls his eyes. "I regret this already," he grumbles, but Sebastian doesn't miss the hint of fondness in his tone.


End file.
